If you are in a big business, you probably do not mind
paying another $1,000 for some fancy OS with bundled support. But if
your resources are low, you will look for cheaper or free OSes. Free
does not mean bad. In fact, it can be quite the opposite—some
of the free OSes have the best support available.

This is easy to understand—most people are not rich and will
try to use a cheaper or free OS first if it does the work for them.
If it fits their needs, they will keep using it and eventually come
to know it well enough to be able to provide support for others in
trouble. Why would they do this for free? One reason is the spirit of
the first days of the Internet, when there was no commercial Internet
and people helped each other because someone else had helped them
first. We were there, we were touched by that spirit, and we are keen
to keep that spirit alive.

Nevertheless, we are living in a material world, and our bosses pay
us to keep the systems running. So if you feel that you cannot
provide the support yourself and you do not trust the available free
resources, you must pay for an OS backed by a company to which you
can turn in case of problems. Insufficient support has often been
characterized as an important drawback of open source products, and
in the past it may have been the main reason for many companies to
choose a commercial product.

Luckily, in recent years many companies have realized how good the
open source products are and started to provide official support for
these products. So your suggestion of using an open source operating
system cannot be dismissed solely on the basis of lacking vendor
support; most likely you will be able to find commercial support just
like with any other commercial OS vendor!

Also remember that the less money you spend on an OS and software,
the more you will be able to spend on faster and stronger hardware.
Of course, for some companies money is a non-issue, but there are
many companies for which it is a major concern.